SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cea2476b2acb04cc72cc6942cc876a6c228981469f5774e143b171109281663c' 
  AND token = 'Tg8tqQ/kfdCfAvahIKWGk5UoyW5WpxgpgnviTWulr44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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