SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d4c29110ef80997f9521d3b195ea4920d92e6c9104cae3f1e8d622918e2b741' 
  AND token = 'QHT+lFX1n/fqunnZ/BZj+OzzJz5XUdSWgVbjwZo5+Hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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