SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c48456f9c50ca7220a28355339bef42d9204829757953dd98e7adf1a35db030c' 
  AND token = 'PaDeb3ojs8Q6Z3zNr6CHDznF1MgmqOPnKjqedMXb+8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}