SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73d3d3513b33099d24b762997ddf87ebbd4f3f2c554fd6f67f5e2433587fa67f' 
  AND token = 'ZHoh5o7x96UJfTh4pvyzmzEcS0kUPttrblGRTP5Hf7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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