SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c7d473a612a419de7dd97ab0729d341df5e45f22802b25b757e164b97aacb09' 
  AND token = 'cLzQlZlKyVk8Sms4zs9yjm0qLHqBqJ25wOJc+tuZ60o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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