SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0ad0493d47e4028fe3bed20666c33ff243089cd3630c5fde9a0471f09199ac4' 
  AND token = 'IlvdOvPNQaRVfQG+O1HwYxkQpXBZ7IwKGfMsi5Dogd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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