SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28a173666118ab6c7019acafcde15a3aca517fe4096bea1edef6d9388437ab3b' 
  AND token = 'C0Q5wxaLBMaEbtEjCOmYWazWkviEwoEUif/529gZ6Z8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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