SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfdd53ccbc0deba97dacf30d582c1241130c41f97f70fc3725f0daef7078af31' 
  AND token = 'dy1f4m+6T6PjZjNi3mMmqiQfHpjwH0BujLLc+mQwWZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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