SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '603ebd63ab35d2843e9a3fdbb6592a2594dda95af7f1ecb9ef95f6d3add12c7a' 
  AND token = 'KQ72XsZ9XdVjaGrz9HsfCbe21ZN9aEUWfA3PVdgLGXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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