SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0342b74610bf3a118ee9eafb5a7880fd169b0fa2d44cac103e09ad159c99d561' 
  AND token = 'LV1xGfcaYbmEgWsI2ZA2EzkiDCgQRi6h3pJRZiEhFso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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