SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06476ee38b5c487ed342ebab10187bfddd753e23cb6815203a74b3b0f3dd8951' 
  AND token = 'I6EQe4c5HJqhXfrM9zHxJYcvl0hJXZxT9Jhd2tfZ7YA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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