SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26dec4511bb24f9414c1c5d41a796580ebb289aeaa243cfd61aaaea4a973fffd' 
  AND token = 'kgosDCTDbLzLI+ejAhuztq0SzJXZyGTuXlLbBwf61Vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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