SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6296a895b5734f778fb69ed36d4e1e41fda77323126eedd800a9c476179c60bc' 
  AND token = 'cm6AlNxCPAHJWqcduG9uqmqEaP2KtpGUm+XFLOASf0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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