SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e5d3eeb32185655b5a665442b62ba9ecb52cc52fbe164ace5dabe7c6e9fc250' 
  AND token = '514z2KFGnubfmDb+WUGojvmJ6rHZZ8HQpWVLXU+qi7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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