SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d150995ba88e32c1c8b315e9a5cb38c9faf84fee41026297002a2004734fc68' 
  AND token = 'CUN7eB4tWL9sHwz4BeoSNY2pX2BgQbWVx3h1eIW3kkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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