SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e65dfb397212410083a48101d7098221e42d83d7cebb70f11e3d8f672a098bd' 
  AND token = '0eBucHHHHnh5uIRI+18SBDTfAbKBYywJloQl/jrl3M4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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