SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '042af797498b630413a697445ec00127028618e8d7e3eaf0c913379470ba3986' 
  AND token = 'unU07G1pv57vowK4xIWS3AgdfChxb6wwLiRVBmLymGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00086

JSON explain

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