SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16df43e518b179398e2f6048a60bd0a28ac8b84f06f3899c648313f0346313fe' 
  AND token = 'otmQq3j86H4PcUuuwbCv9R3YCSSSBGi3iO5JJk253+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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