SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a3e2982b45bc83077e626f3237ec56c99fb17dd62cdc7218c1eea163c732fba' 
  AND token = 'vYehpP8Xk+aVbltUOlfuRovpQw5y0dIRFHqvNlRwGME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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