SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '956abb796033d356d2305d48257eb97c9c9b62efe0e9e184428d7bb4172fd8d7' 
  AND token = 'W/4zAsKZd8JxzpVVXu8uF+T8fYh7gQEW4wV14APA1DA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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