SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5401ce10b83edeeffc327a9278c5cb07e6ad494c96946f119726ffebee47738d' 
  AND token = 'XuSHH6zJIztKvs5vvgjlhowqAU9wYeR8Sk1rSQQtlck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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