SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aa97995595d3d720db7c86a0adee711cfd3fd716a92ed891d9878203fd77238' 
  AND token = 'R9qBVsDSZpz1JhbazW5Upvs4y8kYZhe5H7354U4UKCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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