SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d2bc3ba9f20cc7a3e881c706dc396c25551e8e42fd8461e8636a48b2fbe811d' 
  AND token = 'PjeRsyfw2uHxAOp5fqhAu3NDx989pgUaxqSOQuMavL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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