SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a7dd3d80644e3c0719fede43f60f246609d28b55fa8352fe2226aa6371c152d' 
  AND token = 'rQ/hXSPlnjXwBOQFhQ03cK8ighNqOk8G/BWqnJO6Qn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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