SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e062bb695c40d1f6ed2fcecf0d79933b1dd58998b9ec392fe29cd443a16e47d6' 
  AND token = 'so5oforOVK1lz+lNNTMc3EONA45VtGIUuMGddDDYMEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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