SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0944eb7c7cdb783b02f13bae8d3ffd6d8fba4572c94aff80564d8b1f588cb2d2' 
  AND token = 'xvWY7zwiRqK4VNvGewBVPpus6OBDNWxOMTN9DZnI9Fo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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