SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '190b0c7caf1f72f811135757b373fc688cf723c1fb9b0933f26b5daf76419181' 
  AND token = 'aQZMGtWiXUwVlSZUTihHYvO7GMugwJZlIQfiIWZ9vtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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