SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19a58264b498571f762a91934afaad7c4e5ba783889f4ddd86cdec47fbb8fa15' 
  AND token = 'Eq1oTTc9KL1RPxqoFpGTpkf4vxh2sOpN6k39ewMDlgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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