SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '636a479be8d05da446f7746c503918e5099a466b5b2bdb1ac155c52c51596c67' 
  AND token = 'QGqpY6zAh8VPSs2+GxDSfTyiD1v3wiBcC8TS/OZEskA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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