SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '943d82300f9f25e327e145cb264d523494a28b57bc1dc370d9e558717d95a7f9' 
  AND token = 'CCXJ5eRTVKwVlgxnQoMy6XEzjhxiVJqrFpsaCIV6MnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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