SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef5b375f9f63dd731e66ae4cbf030f51792de344baf27d20e94b657fb92ede20' 
  AND token = 'pJJ9viLbOjY9uU/wr+GZHKT7Liz6cdD6IJR58QJiIBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}