SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3205309a73f1e01297e8850d261eeb93858693c9d73c0aa1e79b140462fea71a' 
  AND token = 'x8s5DkimwxjOOIQr8iGUc5ehrePSqw+yzCu4jemmSS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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