SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32a137242dc66a67e7bd0595210df34ca9e49f536929befc754fc2eda9fb0ff8' 
  AND token = '79wmdb/AwxovTvyV5boYRMFQNFlW9fmm9G1YBjSJ+4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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