SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92707d0ac0f345a90f75d0b9c24d0028bb174eb30527570519c087e8e71d4273' 
  AND token = 'rLvTmvrUlqSzNldjE6/3a2zd7dzyEdrnHVUikhUMK1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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