SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b0e284373de43b2683334a9fcdf38ba956ec26d1d741ca53a7cef2fc9913f51' 
  AND token = 'laylpnNZgxEXXkW6GMCzwpBuzkW5q/BC5szwMRx9E8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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