SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec8af536b178d242c097c7bf4b14f47e19cfb7e362843bb571df02bfd0dbff74' 
  AND token = 'qsnozKamZ9ChD7cOcYxpoNjWqtwd4kPS7VkI08IpdhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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