SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e48c95ced71737d36f3651e0fc18007817d0fd05d74df33434f0f6899ee096b' 
  AND token = 'jmwd6c0EDNWQ7Saw2PZssYe+Dkw1xOc9CNRZkWNXxQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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