SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be886ee6a215e55cf7659e0c68ce2088f63387085c2d3beec562d9bebc0e4352' 
  AND token = 'jy27JAgvYBkTTMs+8WpX74tqEp9w7Sz3XiZ0i9EoKn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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