SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b5a087ce2434f591ca0fb6a0612189875a71787d116020e942f5836da8d3e64' 
  AND token = 'C/C059ylVi5hWVmUnVlkhsP57JruNYGKjA4KIRF16no=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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