SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '623f7315b1888b72f018a8300ea99fec6ccd223099036daa28ec800a614ba7a4' 
  AND token = 'KTGpzSmxRSea22e4Cjq5epqNXM0gBHYfd0X9bdqaCSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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