SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bdfdc79d7d4e7beef9dacfcfaa928fc64bb8634e245fd9080f46a221c1edc6c' 
  AND token = 'JloCW8yZuBHzNNXHUTJrG4rH49pqGHXaaC+EQ8IgtRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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