SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7247cb8112b380ed329f376653655f0ca8e905bb5d9bebc624d499ca6942f5de' 
  AND token = 'N/88uUoxcGgQzCVuqrr5rR6jgpfcaSOc4xQ4sZ93qo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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