SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8193fa21beac4301844ac3439987d6172690e862b9924ce8905f0f863c47bba4' 
  AND token = 's+955A4h9KenGeLBKX2O2qjNgXgL+Q8UH+BYVFERm9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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