SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a634b348a6440f795beb984fa39056770e9d5ebed1246b27503c82bf6f947d6c' 
  AND token = 'pkWuvwzh/4mLVYFFd9K+LWo7OrGu+eoIh31Jc8Uis8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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