SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '356c49ba9718665829069d8c49bcd707bb77057454ed0e09856bd7281231d665' 
  AND token = 'n5o/HTCzg+G9F3BrLvTJfY4PchuA53qvYQ8XH3UijTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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