SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82a52fde3abb24b663b074688308674e2e864b5acee966f59fca5927e0e8301b' 
  AND token = 'VLUaPKpOsLz51ekiVRgkNLQJiUGHnXzv2Gj+hA5guBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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