SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '545bed2f437993fa045e7aefb99429e7e41dcb91abc8315795b5546cc8b0c4bd' 
  AND token = 'M9DjinbPhLQBr61cEuUiYabA8ZirjypT+uhPmR0GPLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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