SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c16ed40f8b64308671c5c70f35498603f018b60395d508d4deee31a054c46c4' 
  AND token = 'KlsOLXZ8BwGAZbg9Dp7CBAqAMAVT4B10O1UV3ROO51s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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