SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56dd8f01d620c6a27550edd073abf29664ff542f75ded64726a7e6fd083398b6' 
  AND token = 'zick7xKqH2X/o0s8SJLlzjVA/xytLQqCk5q25lAIU9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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