SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5669cb8a44f0963797b86c66c27d30d1408b1d82ab50f631672a9d7bfde5d0ed' 
  AND token = 'pt4WduvqW1ryGtGinFtbTOnJgI4ag8yaW9YjmBRKYo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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