SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91479fdc666bf47a4e5bcf8e08c9c6cf3fa2fcfcd478ff0a283dfe85fb8a4a8d' 
  AND token = 'oR8W5b5cUTaiOqCNYa1PG+JihBE4yQWM2htYJYzhn1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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