SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fd9744561563c9e81164fe896c3ff01a263c0d7e07202ca8912953b899d5f69' 
  AND token = 'zObWQSHvZR7XI5jSBpzg2Fq1X75+nwlVhbfCVLgi0xQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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