SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '576472c92f0c0e4845c8b8889f3d8519e88ed41d5737e0852e9d780ad88bb24b' 
  AND token = 'zj7tvjkie/Uwodgfs+hV8b66e/UJPbvKrFIdMGmlV60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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