SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbb3cb53757db35944680cb76e635d1ff2916860c59e90986f9695b20ac61b2e' 
  AND token = 'TVVNDAnBse7q9SIIOKKqpZfUFozT3rw3+OH0lh/VP2M=' 
  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"
    }
  }
}