SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '628e675c6bfb8c61dd237fab4280702b9f7d097bac35367138db2210d93cf63f' 
  AND token = 'jIUBquk08Nv7P93KgWH1qJSWZxSZYrRZfsKY5I8mK2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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