SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65ebe78871c030507b745ff78fd957460c09c600b626ba22c388e9fbad127532' 
  AND token = 'NiRYY+hMVTvALjIfbz7CV4kqOBzha03YioFOHQtCIDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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