SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cd1826be30bf49ad04565725db69fb791314fe778928adfef54c1658c4ea60d' 
  AND token = 'w4VYQcQ4zCH/GEZ9R1/jHI4JiXp4nPUfRmYgiMV/V4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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