SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b309f186b9c71573c9f5bdb234b6a29fcc88b8f1d39ccc46bb2577b81c46db2d' 
  AND token = '7+SdhGPwZvYlXLiKbdDaQmDIYRke+1AMNJuW2u2chNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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