SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae5c2395d95bf1f3f660818f0d441c8a19265e6de2ccc6ef2fa38fd1268bdd93' 
  AND token = 'mzTPVJdQzqOvCXQdyYibjRca2oyDEJaSTszTiIEqosY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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