SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e768ddf0015b507c5033d6ae01408edcaf5953a7886c4616c50288cb7a4549e' 
  AND token = 'FrN4IUYO40lPCeSeOQzo3F7kQV7qctodReZSsGabmkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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