SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e299dc0076ef022668d5104d7ddfbcc993956660896793a13eeb38a98633eb95' 
  AND token = 'ZeDb+GTltlqvzeMnz2536K2JvTidRkpECnQO5r6M3sA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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