SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9067a414f36ff0238631f4555aa98b6d3d4f4d4035210fb176ed52e6166480ce' 
  AND token = 'gtMBdXUyz4gXkCC9R2ra0IQetlUMpob7hoGhSZQ+MvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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