SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4be68abcd55effc299e0330006180c2c7bf7b810eed722915ab16347691d1442' 
  AND token = 'G8OoBkvyjkN1u47Hhm6Z7ScFpvg+3V6IvJg/wfNe6Jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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