SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ecd570eb3351ad5cac9ec590dbb89fd808727b389594b97120031a95aab98409' 
  AND token = 'RgXhrl4e9IDP9b1YkifTYxRBqMT3ao/HCRRNBHJNVYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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