SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82b1bb74ef2b1c6c272e111ec38a13e0ac49f0fe3e86709cff9dc563f3215139' 
  AND token = 'o6BtQxdb27QPAwmBcGUJkvXTWfGNrJpq4QLpXxxARdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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