SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2627f29aae7f3ae03bde4ab8929c9079b202676c5ab6ba1340b7dc14cd209861' 
  AND token = 'jhIyipfjyDvo4vRKVDqZpFy4pkYU4X3aq/PVtrBIFig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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