SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e97c9f3e1157abdfc51cc3828c1f859176ba7b8e2790b08ddbe82922a82762b' 
  AND token = 'v/naOPzD8OAB7ZK9FurzZ1QMn+3LRPdytHoKv7JBZqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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