SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14d84195b3b6555e55205da1c2061c070bdbddfe95583377ea08d21f366e2bf9' 
  AND token = 'ZEOsxMK8kjvCBp3E3GSfxvfjJ8Exfd1ILlJx3sTMOJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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