SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd73217196d5b311bfa79a48361682726882c29582b4b15cb4076d9d71ca601e8' 
  AND token = 'CDDA3eBsKydTTWh2ydiX61dhyk0YbKcC2lecs94Xxy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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