SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c2dde290b90f6e88d2cfd8e9553a66b654b0a5c4f92218c422097df09c8a7d7' 
  AND token = 'Y5+iGuJlzdp0gHilsBWEjjv+zDyLRFsMBuhtzLs+lHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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