SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33f08adb5bff91816ed2cab4fa488d89b28f645ffbe0dd59fbbf0b4994f49812' 
  AND token = 'AhfN4hGwi2HwbsOdFvyYjb3SloKGrFuPybpVjFjpFqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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