SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d54d7b48a835dca5825af76ac626221a7cd03e7cf24abaa66b4ea4f650895bd' 
  AND token = '8W34NL7LuVDRfhqk+2EN5qBHYoJvTYUNzMVNlPOhS6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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