SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b08003deab3547b63e63c2d2b52cb9818de9aa8111c462667bd08f9e329fa77f' 
  AND token = 'ibua+ja1mFkSyJ/5xIlUwKNO39DmhGN0BsHwcznnT/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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