SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9730444f04f126c4820f441828bc3960a6394eb19f7bb08ad64b7c20c7b79fbc' 
  AND token = 'HPHTenRmv1K/a9/iGoQCMzNuCDoyOYQ1+RQt4TNVF2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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