SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc5eee845d1b689f94a4efc5dd291dc1127cd82b6dc5cb5e38a7716c26ce64c4' 
  AND token = 'f/57aRap4ePxwZY52AsIAlODWsvqdycFbuq9Qjm8Pcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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