SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08efdb04947b813e63959d6654643eca164ac6c60d575ffcee76e1d6469a0abd' 
  AND token = 'YK/Dxvwxwgkd7tbevoUe4LxMHJ8B5RmdFYoc/ssZNj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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