SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '471c6cebc9a71d5c251e85910ba5feadb76a90bdde5e63dc6017f015441e07a9' 
  AND token = 'mx4laGM+8/7/2oRzF2wWEF3lhTF4CwK2YbMdIy6UvdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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