SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00ef836e5a1341c29d97073d7e95b31304e1a8e1535dadd814f26f18b0a7e227' 
  AND token = 'bj/FcvGAUZ1TjYx/m+qWY8NZbzBJjW40AQhinF3dIRA=' 
  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"
    }
  }
}