SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f317f190d3c8544b9d52687a5e06f1d464c108dda2ca5a24595acbeac587c698' 
  AND token = 'it93KuAK+nqQaoFdDI9urPdyGWO8onBiR9b9PguOOq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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