SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89522736983163d37884bb2440170a96ce106bfa2223f90fb8dbfbf7aa381449' 
  AND token = 'bY0ImkizKjjOhOjJqkn2NngccPAOiOefQn/wdblXLbc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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