SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c65e806ec1874cceb94962482487e77f2b56c0072860ab63b29cf14a4fd5979d' 
  AND token = 'csU7kv6T6Vf8VuwF/OHiL/4AhUcQQetMowoUcSDIaHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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