SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f6186825047ec5d59185fe6c0dade539a329980b93f5a1d5156a030c52e972c' 
  AND token = 'RqnePcXdP1qZhf4AzF9HyikF9dfeJUtATbrq2/7Ls4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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