SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fec5c1b864a58ac30744c77ab3176f96a5fc3ca9c241ed64d0c2555110ced18d' 
  AND token = '+erfwv0xJCwjDvVOz+4DWR1CFTwjZGEXxqw1iGIfoMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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