SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd20e3d96bea4a10e7b4841165034fbb73c339b459ef9d342192d0827cc4dfa1b' 
  AND token = 'wwAE8rntjv3M5GsPxoKzn/MaH2eQkBZ/AaoG+2rNRRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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