SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ea4bd79ce50773cbcc6689e05d2d8d0f751d875db776756748a6ca8b75a68af' 
  AND token = 'U69pk9IeESJXaub7pru/3jTpoF8EPY6/jE1Bi4gFQJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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