SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3aa3f61481f49be3aa53843c6942830264dfc4238578b0a32e061eee4d7572b' 
  AND token = '8pwFxohK77qEKJ5yYHCnmd0Uj+rfbV8jJeLWGI7y9YE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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