SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '528783af19897604710c800d1ab4a3bef69ccb561807c23b6487fc64b74cf19a' 
  AND token = 'MA558M40G2r6JY6E2xUN9g6JH49P0P1lRHeuWGYshMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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