SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe385326d81f85ff6bc42a4f646813d0ce4ed8f242ccf60b67809d7cacfc240b' 
  AND token = 'pXVS6dmqNgaGsnV2o1InvuDPsPn2DYBN55mjom93+oI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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