SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71c7f212a2baedc014f3c528615de971a17ea8ffa24c402fd7a1008f3a9e4126' 
  AND token = 'cqn9xPvhR9X6KsWhYBDBh9Gt2COUMD/kHOqknoYqzX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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