SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c5528700e3db05ac46df80460d992c823157eb83b865a273712f648f322030' 
  AND token = 'BD87iooSjT/E0FgslkqsJ17UJAfmhRiWph0vdl+M5hk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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