SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cdaee6c04431db5818e785665795c995d9abc22a17cb19000cbd88b732f322b' 
  AND token = 'irr7SiG325DA7Zt47deEfmGUxu/5kBjQMCMPpLIVzyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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