SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87289375ff3628e3e724e7cb986d5955dc41308c443d22457ab776e0a9bbc211' 
  AND token = 'KrgsfkzRGQl2BLPmWy31jStzQQ1h9QfffzYnrdRDk9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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