SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3a34f542193c6651098c54e8d609b6b3c247ccf93e721c77c1598f46579a80f' 
  AND token = '1g2jiHJwr8jZhvIBy0s/Ax6PCM47JIXjvPgbIjRQAOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}