SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18570cf9ca91bf797203bd8248e7b0cf412eea934c49315d5f287ec6f9a534bc' 
  AND token = 'zhavlDc4pO/WTAzB+Wkzwkt0mJzY8yXzEoY0C6Tu/5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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