SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4e812fe3281b929f0881309dd0ce24638c29fdfbb5b52a827a61bfa954b165a' 
  AND token = 'Sg2iS1HkilDg2jzsjMaksTbBinXUfktJ1NJYpoTLgMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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