SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54077794f21ec146c188f2136af9bb5d39cab3a30a04cf230fd89d30f0dfd380' 
  AND token = 'HYis6u1gjgy/qAwTSEv+TlpkPE76/DuBCOYVCjJHE2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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