SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b9b38f5f87ae7f405c18ae91ce31fa34c63d59e3992eff5f9e8ea0b91425c3b1' 
  AND token = 'qmDHHGoWFCTujDO3OQLIm+qfYVALjhuDVBM8QRkW16Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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