SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d1e75829e37eb754b18213efab968684ef783d46f8a7b5268f5fe89def29ac7' 
  AND token = 'Dwp/B9G4vtftSeJrJUtST8y7JUlyPTRrYd1QHvZZgro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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