SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c9241fd0991ac3a95fc69b968e42e3f51b346502e3b13113ebfe81b54bb28f8' 
  AND token = 'MxNbB+FSdVCUxEGTOizeqkEi7q6hJI2k2IkZcfIh8ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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