SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7d69910f645c58f389099e50e560425f96f0dbbe0c2d9297d5395da09f5d695' 
  AND token = '2vYHDOestDyllF6O/wnjj3o/msQQzt6kl9JUekQl4xo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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