SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93a7b6ae76e338ff68d1c46730bf41e2e008355d242b4d255f12b624ebd7c790' 
  AND token = 'ATSNas4jfKqttOwlOIx33ZSv9PXYVOU7yy9nBhhLcBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}