SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f8613681f34aa32153a9a98f4fca895cbeb1379c9b5d4813aabc270ff2ae57a' 
  AND token = 'WwW277bqzxeoaWFkAvwpjC2APiKpRQkkd4/pMwBOVsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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