SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26d71b58f34107828319893d61af825a42d735c42f6c4dd0a1817edd458ee883' 
  AND token = 'iYVB2/Fb2MnkSeagmYipEpUh9g5AO7xl9ZqZE5fGNJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}