SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5b4248d8b3b2fb1a02b5174a823b7188a8a719241afdc22b8dfc2a65931c84b6' 
  AND token = 'cvNXro1W2D9Ht+wjoMO7DWB4jj2p6xE+vnGnXKqRhCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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