SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd846ea88321ab141c8003fbf18882c7c8899a1eacba476bce9f9bba983c5b13d' 
  AND token = 'd6PlrV31REh+e8VVjowoIq0gZNZrj0ogQ6pUkUvqqbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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