SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bd9916c7457e45eda5b3b50aaacf5f7509cc34501dc6ba7ef6f99c42a101bd1' 
  AND token = 'f9c6AH2eztNdUoIBX+Xd/ydwkhcDbsw+MUkmoAWg5aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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