SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dee98a6e3fa0e143754e5564e3f3179fa5364fcbfaa61e049242ac48a1e34be6' 
  AND token = 'AEF1O4gRYctdxA5VXwSPmPWMI1YDj1Uy4pEuVGRztHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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