SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19361bf59e11f20cd28c644f3129edd51f44b4c1fe843fcdbbc338187247ccf3' 
  AND token = 'wMghRyIepwnUCGiE1ut2ziSxE9MehhyyBKyTMGt3eZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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