SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '348d70adfb69b1de5a37e1ec5ba065271be57e01bb0378824d3a032d903bf464' 
  AND token = 'Vn80qg1VnXWxohqqJtO/0ou2+NtJ/LgzzU4TagDx8xk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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