SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '289022905839b3b60b18425ceb68f263d4465a2553783a4d145130af58e3e5fd' 
  AND token = 'qnK/Ou/Blhh/anIQ6jJxCCnwSy1JiHjz9dveLfbww5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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