SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '362cf31ee6f0fb294b1fb01d6ef0ff0c39f9bdaa6c3863d3d042f9db34da3103' 
  AND token = 'p57wTHakcJcgVSJ8xNKKCC2aNRC9w5SnVgN1tPUsozo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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