SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58593a8c37959042e62d6e1546d16576c6cda474d8cd3192e590032d64e37d10' 
  AND token = 'iOy1BnihUxYNYNqP7WYI/oywacJpsKHcJUz2hHzxSx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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