SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a966f443993eeb91121d687bb35e795bb6a0ae7a62550bb7065eb533f86d5c8' 
  AND token = 'Uwel9H4LZvwPHJuTZzPRVa8nNORrtZaCmQ3PsDpu8DM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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