SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd86c1a4c75773bb76f8b09e82725323ddba5966dbb0a4e3f087b3b5e724271db' 
  AND token = '2rN+unCpEk6xsUdRggmZsjOzTnJBLJ46nvxYOOGQtqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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