SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '240a562c7f1273bf8b44da7b82ad2bfafcacfab0d9282b685b9c29fc621dbcca' 
  AND token = 'QySPYAj2kOhw9p62bXqBlwvtay9MfYG1Be/Hbfil7yM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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