SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c12c3219119ec08d73158209b21e347db1d59549360c02a6bee58199cb5d437' 
  AND token = 'JW7bbbphw9UcwoWIziQt1+kscNY8zCMX52qJsrqB+LU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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