SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83b3aa2f9cced10c8637d9a290b809f2bb417fdfebbb846ca822a3e43e5ac398' 
  AND token = 'sefng7fVBwErH+RInWIt3mV3zDqo1I75nHRJqrs4pjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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