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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '911a7f738a62b8273a51e3c88bdadfcb2a91a29a4bce38d70100cc47efc9d08b' 
  AND token = 'AeFBycGDmzzCxVBqFsEuPlVyH/ctVsY6Zmw9R+NeOD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}