SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fabbd1140475ddb6bba1165ed552d737c79274f6d70573e1041ac066c35853bb' 
  AND token = 'XR5iIvSwJI5HOwH+Z71ecs1fdsvuUorepoubkIBhbdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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