SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23126c0dfb847e0d3b9cd4683fe74f91612d7a773ba5957af695ff5952974a85' 
  AND token = 'loOqVi6Gc4A76i8LMFGpZZ5Bjqb336vqaXwWY3ENGY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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