SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2641c6c6de6e483ffeda7e1e867c154be86b9279caf809981d8e4d07a4b37499' 
  AND token = 'IKoxBoX8OffqPPh/lqzJlUU7tzmJIhUN3AN2HZe4GEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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