SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88725f363c4e7441bcf3d72e2ded6fde6acf042a18608f560c59da8bf08c8435' 
  AND token = 'mWX/Rnk1kBI9XKARdWiPWhTRnCVpB/loFK2hVXnPMSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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