SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25ce3e57a94a44369890137627b35a284e78b760a0bc0adbe2fd7cbd95cead7c' 
  AND token = 'Cu/XzJXkVZEd4a9Cv1/ie7d0eyFca3NQL4TnxMRGIf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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