SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f83a2036845bcf237ec93ec24341ed79ef5c1e5a84d5a57d37065928e8d6f57' 
  AND token = 'byyZ6dk5vXsGrjKQOtzY9StPRRZLNz9UwxJNCCAZrcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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