SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53891eeee217089f97396c0569a8c01340b50dae68b5da59c8686f650fbf6955' 
  AND token = 'KBPAvEW6GJS+/5vosV0GblQDtxw+GcaspAwcQk7trTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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