SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40b9386152f8ebcf611a7dacd79b4abd10407b8e29a94139dcf93bf9c39c0067' 
  AND token = '3fKWjDbLkmXeo/2/B4uVnxZv4Uqp/vkDGQeHgmLIRF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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