SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '062b5b6b343d5ba164170640960c824398153f81bdfc0f6a35bfc29fc770618b' 
  AND token = 'YVzgwRYPKJLgT7R1tldEBSBsh1EqqvkykUwHKp1oUko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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