SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4429f441fc1472fdf959e33db2eca542670673c6ea182a4e71b65d89603754a' 
  AND token = 'KnRXIPKNJfN+lW6ZL2yozNrcm+OSg9U4BnEwJ0jSdP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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