SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7adc66c1ec45f57131e9b8bf88c2562114a9363840fa66def835ef201285960f' 
  AND token = 'Zpl7wmdT6rGKHMiZ3UvIKFc4BzERtYE+dDx/gi2GQ2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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