SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4647b43722359f6c4faf962c2db45511cebb1921359758824f05bf75bff4ecde' 
  AND token = 'zOl7gVKpZ7r08GuEsb5PWeKVFXXC0FY2aL8VMmmZoJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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