SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '929d22344a09b3c6238eafeb0679a327bec9cff8fbe841d4a7e474f66909bfd6' 
  AND token = 'X0hsJTUv/9agxXKeMep/b1KiJsEfAUcXwNR3BhyGmFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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