SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '146a273be768a844686867ffa86f231aa9f793569050f3a5d3496b6af74f858e' 
  AND token = 'O/JvoFvEwhZ+giceHtOPct2sskvEJqmgdPFsPcGl19M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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