SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a62520dac71e3677e2bafd046d461c6fdef613957b2f8ac5a4121175a30015d' 
  AND token = 'q/PgGSc7pIEJJf+ZqGMkp/o3YJgXy/D97pb9XmAKmn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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