SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73da53f936b772b84ae462170d0230010e93f1629445776471568e2a8ffddc1b' 
  AND token = 'yuCFfCa5riaMwaZKWmGfvsDDgP3l56U97aWNEUTgwvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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