SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba65620bfd85b2fbc02384ccc2407b52cacb11034a0ff8b52d263325df0ff1b6' 
  AND token = 'acbAlgyb4zPmE0j3QZRuHcm+GAstLE6lGBdzu4yCEHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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