SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e24dcd0c0ba46c06f71a603bf07f6b633afd05cb0793d74247a5cdf3d4b7b17a' 
  AND token = 'tdj/T9+bkVBle7c8YOhkTpEBc9zAnG/B/jkH+t3NH3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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