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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eca5692cd1e6884901a7e4b0524b1753684ba275a50ee16c6d10ee888d59a83' 
  AND token = 'y0QDfaglqbbS6E5qb3TTyS5HAMkCh/7VVMclWxktNlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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