SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cce7decb1b8dd33c21470792e8422fc4e31c3cec0364e28cb3a95fedffba697' 
  AND token = 'bdhqzaPdjr2Jqg7+Ey0ebSf4bxKlZgXG2lvevWKaIpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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