SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd36fe65b1f85259f34de87bd72657cc1a4af0a44b7650ba417a0f7099f8fe5ca' 
  AND token = 'SUmBIXaGTEytTqpjBVCMQ8tldxFfrTzYUOsBx4MpZxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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