SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ea1204cb1e4b66b9ffd4581d826639569fd4d32affdd47b7f2edddc2d14bc7f' 
  AND token = 'TTzE8moDKVWRh5UIMYPkatwxjaBsHH1ac0CyOBlN+pI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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